Distributor Busings

[Don Keller]

I'm installing a new main shaft and cross gear in my distributor. I decided to replace the upper and lower bushings. I ordered the tool but it looks like it's in installation only. What is the best way to remove the upper and lower bushings?

I also ordered the button with my new cross gear. It looks like I would need to drill a hole to accept the button. Any advise on installing a new cross gear and button.

Thanks
Don

[G B.]

Removal tool

I'm not aware of a ready-made tool for removing distributor bushings. Kent-Moore might have something though. You can check their website for clues.

I made my tool out of an old distributor shaft. I cut off the advance plate end of the shaft and filed it flat. I then selected a small, thick washer for its strength and diameter (slightly smaller than the O.D. of the bushing).

To use the tool, I place the washer on the bottom of the upper bushing through the empty tach drive boss. I then insert the cut off shaft through the bottom bushing to rest against the washer. I can then hammer the upper bushing out.

[G B.]

Removal tool

I'm not aware of a ready-made tool for removing distributor bushings. Kent-Moore might have something though. You can check their website for clues.

I made my tool out of an old distributor shaft. I cut off the advance plate end of the shaft and filed it flat. I then selected a small, thick washer for its strength and diameter (slightly smaller than the O.D. of the bushing).

To use the tool, I place the washer on the bottom of the upper bushing through the empty tach drive boss. I then insert the cut off shaft through the bottom bushing to rest against the washer. I can then hammer the upper bushing out.

[Jack layton #896]

Re: Distributor Bushings

Just replaced my mainshaft, cross shaft. washer, brass screw in adapter
on my 1965 327/300. I bought it all from Dr. Rebuild including the brass button. E-mails from others said that the brass bushings seldom fail and generally do not require replacement. However. the end clearance generally plays a much more important part in the life of the cross shaft/main shaft gear interface. Therefore one should tighten the clearance by using the special washers(still available from Chevy). Mine had room for 3 washers @.032 each. As far as the brass button goes I have no idea how to make that thing fit. There was no button in the distributor originally so ????. I rebuilt the unit with grease and omitted the brass button. I did make the mistake of putting the lower gear on upside down but corrected that later . Also aligned the dimple with the rotor. I have a 100 miles on the motor now and all seems to be working as it should!!! KNOCK ON WOOD!

[Jack layton #896]

Re: Distributor Bushings

Just replaced my mainshaft, cross shaft. washer, brass screw in adapter
on my 1965 327/300. I bought it all from Dr. Rebuild including the brass button. E-mails from others said that the brass bushings seldom fail and generally do not require replacement. However. the end clearance generally plays a much more important part in the life of the cross shaft/main shaft gear interface. Therefore one should tighten the clearance by using the special washers(still available from Chevy). Mine had room for 3 washers @.032 each. As far as the brass button goes I have no idea how to make that thing fit. There was no button in the distributor originally so ????. I rebuilt the unit with grease and omitted the brass button. I did make the mistake of putting the lower gear on upside down but corrected that later . Also aligned the dimple with the rotor. I have a 100 miles on the motor now and all seems to be working as it should!!! KNOCK ON WOOD!

[Don Keller]

Re: Distributor Bushings

Jack,
Do I use a general purpose grease and full the tach drive shaft area?

I have one thrust washer on the tach drive cross gear and without grease there is a little bit of movement with the cress gear. I don't believe another washer would fit unless I did not tighten down the brass coupling. I would tink that would be askling for trouble.

One other question, Under the breaker plate there is a resovior that is covered by a plactic washer, do I add any lubricant to this area? I removed some gunky stuff from this area.

Thanks for the help

[Don Keller]

Re: Distributor Bushings

Jack,
Do I use a general purpose grease and full the tach drive shaft area?

I have one thrust washer on the tach drive cross gear and without grease there is a little bit of movement with the cress gear. I don't believe another washer would fit unless I did not tighten down the brass coupling. I would tink that would be askling for trouble.

One other question, Under the breaker plate there is a resovior that is covered by a plactic washer, do I add any lubricant to this area? I removed some gunky stuff from this area.

Thanks for the help

[Don Keller]

Re: Removal tool

Jerry,
I had no trouble removing them. Thanks for you help.

Don

[Don Keller]

Re: Removal tool

Jerry,
I had no trouble removing them. Thanks for you help.

Don

[Jack layton #896]

Re: Distributor Bushings

Hmmm? There is only one washer on the cross shaft. The clearance of which I wrote was at the base of the distributor between the driven gear and the housing of the distributor. This space from the factory is generally
very loose at 0.100 inch but it should be more like 0.010 inch to 0.024 inch. Hence, three washers at .032 inch is 0.096 inch which leaves a clearance of .004 inch. Which is only 0.006 inch off the optimum. I think Chevy also sells this washer in a much thinner version ( 0.010 inch ? ) to more accurately fine tune this clearance. I believe it notes the usage as being for the F.I. distributor but I feel sure it could be used in the regular distributor as well. If there is a lot of space between the driven gear and the distributor housing then I think the main shaft tends to get forced up by the camshaft gear , perhaps causing a mismatch between the mainshaft's gear and the gear on the cross shaft.
As far as grease goes, I used a multi purpose automotive wheel bearing grease. I smeared it all over all the moving shafts and gears. I did not "pack" the tach drive housing. Just smeared a liberal coating of grease.

I am still curious as to what that brass button is to be used for. I assumed that if the back of the tach drive cavity surface needed to be ground smooth then one would somehow adapt the brass button to make up for the lost metal.????.
The fellows who actually make these components are down in FLA.
Bill Fisher @ HiTech Innovations 4625 Panorama Ave. Holiday, FLA 34690 phone# 727-942-4003

Maybe you can call them for additional advice. They offered to rebuild mine for $220 but heck I wanted to have a go at it myself. I figured they still got their $'s since they are probably the suppliers to the retailer from whom I purchased the parts ( Dr. Rebuild ) .

Also try a fellow named Gary Wylie gdwylie@ziimaging.com
He sent me an e-mail with lots of helpful hints as well as a number of other folks both here and on CRPL.

[Jack layton #896]

Re: Distributor Bushings

Hmmm? There is only one washer on the cross shaft. The clearance of which I wrote was at the base of the distributor between the driven gear and the housing of the distributor. This space from the factory is generally
very loose at 0.100 inch but it should be more like 0.010 inch to 0.024 inch. Hence, three washers at .032 inch is 0.096 inch which leaves a clearance of .004 inch. Which is only 0.006 inch off the optimum. I think Chevy also sells this washer in a much thinner version ( 0.010 inch ? ) to more accurately fine tune this clearance. I believe it notes the usage as being for the F.I. distributor but I feel sure it could be used in the regular distributor as well. If there is a lot of space between the driven gear and the distributor housing then I think the main shaft tends to get forced up by the camshaft gear , perhaps causing a mismatch between the mainshaft's gear and the gear on the cross shaft.
As far as grease goes, I used a multi purpose automotive wheel bearing grease. I smeared it all over all the moving shafts and gears. I did not "pack" the tach drive housing. Just smeared a liberal coating of grease.

I am still curious as to what that brass button is to be used for. I assumed that if the back of the tach drive cavity surface needed to be ground smooth then one would somehow adapt the brass button to make up for the lost metal.????.
The fellows who actually make these components are down in FLA.
Bill Fisher @ HiTech Innovations 4625 Panorama Ave. Holiday, FLA 34690 phone# 727-942-4003

Maybe you can call them for additional advice. They offered to rebuild mine for $220 but heck I wanted to have a go at it myself. I figured they still got their $'s since they are probably the suppliers to the retailer from whom I purchased the parts ( Dr. Rebuild ) .

Also try a fellow named Gary Wylie gdwylie@ziimaging.com
He sent me an e-mail with lots of helpful hints as well as a number of other folks both here and on CRPL.

[Don Keller]

Re: Distributor Bushings

I'm still waiting on the main shaft shims to come in. It looks like I need to add a couple to tighten up the mainshaft. I didn't realize these were the washers you spoke about. I was wondering how 3 washer would fit on the tach cross gear. At least on mine it't a pretty tight fit.

I not sure how the button works either. The only was I could see it working is to drill a hole in the back of the tach cavity on the distributor housing to receive the button and grind the end of the tach drive shaft to the proper fit if needed. There is a worn spot but very little play.

Thanks for the information.

Don

[Don Keller]

Re: Distributor Bushings

I'm still waiting on the main shaft shims to come in. It looks like I need to add a couple to tighten up the mainshaft. I didn't realize these were the washers you spoke about. I was wondering how 3 washer would fit on the tach cross gear. At least on mine it't a pretty tight fit.

I not sure how the button works either. The only was I could see it working is to drill a hole in the back of the tach cavity on the distributor housing to receive the button and grind the end of the tach drive shaft to the proper fit if needed. There is a worn spot but very little play.

Thanks for the information.

Don

[John H.]

Re: Distributor Bushings

Don -

The cavity below the felt washer and plastic seal is the ONLY source of lubrication for the upper mainshaft bushing - only the lower bushing gets engine oil. GM sells a special lubricant for this, but it only comes in large tubes (to do hundreds of distributors) and is very expensive. I use a gray moly lubricant for this application (I use ARP Assembly Lubricant, I'm sure other similar moly lubes will work just as well) - same stuff that's specified for lubing the I.D. and O.D. of throwout bearings.

[John H.]

Re: Distributor Bushings

Don -

The cavity below the felt washer and plastic seal is the ONLY source of lubrication for the upper mainshaft bushing - only the lower bushing gets engine oil. GM sells a special lubricant for this, but it only comes in large tubes (to do hundreds of distributors) and is very expensive. I use a gray moly lubricant for this application (I use ARP Assembly Lubricant, I'm sure other similar moly lubes will work just as well) - same stuff that's specified for lubing the I.D. and O.D. of throwout bearings.